The present disclosure relates to an image forming device including a developing device.
A known conventional image forming device which forms an image on a sheet includes an image carrier, a developing device, and a developer container. When a developer is supplied from the developing device to the image carrier, an electrostatic latent image formed on the image carrier appears as a developer image. The developer container includes a developer discharge port and supplies a replenishment developer to a developer replenishing port provided in the developing device.
A volume supply type developing device is also known. The developing device includes a developing housing, a developing roller, a developer transport member, and a layer thickness regulating member. The developer transport member is rotated in the developing housing to transport and stir a developer. Arrangement of the layer thickness regulating member so as to be opposed to the developing roller regulates an amount of a developer to be carried on the developing roller.
Additionally, in the developing housing, the above developer replenishing port is opened above the developer transport member. In the developer transport member, a transport capacity suppressing portion which partly suppresses a transport capacity is formed downstream of the developer replenishing port. As a result, a developer retention part is formed around the developer replenishing port. When the amount of the developer in the developing housing is increased, the retention part seals the developer replenishing port, so that an inflow of a replenishment developer from the developer container to the developing housing is regulated. On the other hand, when the amount of the developer in the developing housing is reduced, a gap is formed between the retention part and the developer replenishing port, so that the replenishment developer flows into the developing housing from the developer container.